Decreasing size process in the cave (Pleistocene) lion Panthera spelaea (Goldfuss, 1810) evolution – A review

This study analyzed size changes in the course of the time among European Middle and Late Pleistocene lions. The general decreasing size as a tendency in cave lion evolution is confirmed. The whole time span of lion presence in Europe was divided into four main periods. The first period covers Middle and late Middle Pleistocene (MIS 19-17 to MIS 7-6) and is characterized by the presence of very large individuals with somewhat primitive morphology. It might be cautiously said that lions in that time were comparatively large throughout the Middle and late Middle Pleistocene. The second period included the last part of the late Middle and the beginning of the Late Pleistocene (MIS 6-5). This period is documented by a mixed presence of large individuals with somewhat primitive features together with smaller, evolutionarily more advanced dentition lions. The third period covers the first part of the last glacial, from MIS 5 to the beginning of MIS 3. For this period, the occurrence of moderate sized specimens with evolutionarily advanced dentition is documented. The last period began with dramatic population decline and genetic variability reduction. It lasted from MIS 3 and 2, and within it size drops sharply. Among moderate sized specimens, very small lions with somewhat lesser posture also appeared. Asian or African affinities as a result of a new migration event for those dwarf lions could not be ruled out. Size decrease showed that Panthera spelaea was a dynamically evolved species. Thus, the size does not seem to be a reliable criterion in determining the age of cave lion findings. The general overview is complicated by the great sexual dimorphism, local evolution and extinction, climatic conditions, and migrations. Size changes in P. spelaea evolution cannot be used as a useful biochronological tool.